1. Field of the Invention
The present invention relates to marine safety devices, and, more particularly, to marine crew overboard retrieval systems.
2. Description of the Related Art
Marine crew overboard situations are potentially a matter of life or death. Even if the overboard person has on a flotation device, an injury may have occurred before, as, or after the crew goes overboard which renders the overboard crew unconscious and/or unable to assist in their own recovery. When the temperature of the air (in ° F.) and the temperature of the water (in ° F.) add up to less than 100, the risk of hypothermia for an overboard person is likely. The average person in the water in such conditions and without a survival suit may only have about fifteen minutes or less prior to the onset of severe hypothermia progressing quickly to unconsciousness and death. If the overboard crew is injured, the injury itself may pose a severe risk to the overboard person if not treated quickly, thereby further necessitating a quick recovery of the overboard crew.
The phenomena of “dry drowning” is known where cold water inadvertently swallowed by an overboard person can cause their esophagus to spasm making it difficult or impossible for the overboard person to breathe. A person can suffocate and drown under such conditions even though their head is out of the water. Obviously, in wave conditions particularly, the longer a person is in the water the more likely they are to swallow water.
It is quite common for recreational boaters to not have on a flotation device even though the flotation devices are at hand on the boat. Additionally, many such boaters have limited or effectively no swimming skills. If such a person goes overboard, even in the calmest of conditions, the threat of drowning is immediate.
Unlike driving a land vehicle, there are no licensing and/or training required of a recreational boat operator. While excellent training is available for recreational boaters, much of it is in a classroom setting and therefore does not include hands on exercises. The hands on training available to boaters is taken by relatively few recreational boaters. Exacerbating the limited training on the part of the crew and/or skipper is the conditions under which a person is likely to go overboard. High winds and waves can challenge any movement or action on a boat and make the boat difficult to handle even for a captain and crew well seasoned. For example, typical hands on sailing classes, and standard sailing texts, teach a overboard crew drill where, a crew yells “man overboard” at the onset of a crew overboard, spots and points to the overboard crew; the spotter or another person throws the overboard crew additional flotation; the helmsman maneuvers the boat through a FIG. 8 to a downwind location near the overboard crew, being careful not to run over the overboard crew, and stops the boat; a line is thrown to the overboard crew; hopefully the overboard crew can get to the line and somehow stay connected therewith; the crew is hauled close to the boat; and finally, the overboard crew is hauled into the boat.
However, in the Great Lakes for example, expediently executing a typical man overboard drill in 3–5 foot waves and 20 knots of wind is close to impossible without risking further injury to the overboard crew by contact with the boat. Any boat has effectively no steerage if not underway. The combination of wind and waves, and the windage of the boat and rigging, make a boat difficult to stop at a precise location relative to the overboard crew. The difference in drift between the boat and overboard crew can be substantial, given the fact that even a relatively small boat may have hundreds of square feet of surface area impacted by the wind, even with no sail up, whereas an overboard crew will typically have less than one square foot impacted by the wind, given the fact that only their head will be above water. Additionally, the wind velocity increases as a function of distance above the water, so that the taller structure of the boat will have a greater wind impacting it compared to the close-to-the-water head of the overboard crew, thereby further increasing the difference in drift between the overboard crew and the boat. It is surprising how quickly the distance between a boat and an overboard crew can increase even with a 1–2 knot differential in drift between the boat and overboard crew. For example, for a 1 knot differential in drift between the boat and overboard crew, the distance between the boat and overboard crew will be increasing at about 100 feet per minute. Therefore, in a minute or less the overboard crew can quickly be out of reach of a throwing line, or if connected to the line, can be towed at 1–2 knots thereby making if difficult to breathe and stay connected to the throwing line.
The head of an overboard crew is a relatively small target to track in calm water, and in even small waves, can quickly disappear from sight behind a wave. If the waves start to cap, the overboard crew becomes even more difficult to see and can be continuously dunked by the capping waves. Capping waves with spray can obliterate the surface of the water thereby rendering visual contact with the head of the overboard crew very difficult.
Skipper and crew experience and training vary widely, but the skipper of a boat will typically have the most experience and training. Even so, the skipper may have not prepared the crew adequately for a crew overboard emergency. A typical scenario is that a boat is taken out for a leisurely cruise on an idyllic midsummer day, the cruisers are not paying close attention to the weather conditions, and a summer storm picks up quickly and overtakes the boat. Storm fronts can move as rapidly as 30–40 knots and can have winds in excess of 60 knots, which winds can quickly change the sea state, and the leisurely cruise is now a potential emergency situation. Conditions are rapidly changing, and in a worse case scenario, the skipper goes on deck without proper safety gear, such as personal flotation and a harness connected to a jackline, to adjust some rigging and a strong gust heals the boat sharply, and the combination of the force of the wind, the healing boat, and possibly a wave simultaneously hitting the boat, causes the skipper to lose balance and be knocked overboard. Now a crew which is not prepared for gale conditions finds itself in an emergency crew overboard rescue under storm conditions. It is easy to imagine how this crew would find it difficult to execute the multi-step crew overboard process described above, even if they knew what to do.
Another complicating factor can be a shorthanded crew. A skipper and single crew well trained in crew overboard drill can execute a single handed crew overboard in the event that the other person has gone overboard, however with increasing difficulty as conditions worsen. In difficult conditions the skipper, being the most experienced, may elect to leave the cockpit and go on the cabin top, for example, to adjust or secure rigging. The skipper is then more likely to be thrown overboard leaving the single handed crew to not only handle the boat in potentially difficult conditions, but also conduct an emergency rescue. If a crew finds themselves in such a scenario the single handed crew may develop a feeling of panic thereby adding difficulty to any rescue.
Slings are known for crew overboard rescue. The sling may be a flotation device in the shape of a closed horseshoe, for example, and attached to a line which is attached to the boat. The sling is thrown in the vicinity of the overboard crew, or thrown in the water and then maneuvered toward the overboard crew. Given that the sling has a lower profile than the head of the crew, it is easy to loose track of the sling and/or overboard crew while maneuvering the boat and attached sling toward the overboard crew while also maintaining a safe distance between the boat and overboard crew. In addition to the difficulty of maneuvering the sling to the reachable vicinity of the overboard crew, the overboard crew must be able to position the sling under their arms, which can be difficult for a fully conscious and uninjured overboard crew in high winds and/or a difficult sea state, and even more so difficult or impossible for an unconscious or injured overboard crew. For example, if an overboard crew is able to get hold of the sling, and then lifts the sling out of the water and over their head in order to place the sling around their upper body, a strong wind can tear the sling from their grip and push the sling substantially away from the overboard crew thereby necessitating further maneuvering of the boat and sling to reposition the sling near the overboard crew. Obviously, for an unconscious or injured overboard crew, the sling system holds little or no advantage in the retrieval of the crew. Such a scenario may require putting a rescue swimmer in the water to assist the unconscious or injured overboard crew with the sling. Even a strong swimmer with rescue training will find such a task difficult, particularly in difficult seas. Further, placing a rescue swimmer in the water may be the most dangerous option for typical recreational boating amateurs, relative to the safety of the crew and boat, particularly when there is only one crew onboard to begin with.
Another option is to radio in a mayday for a rescue operation executed by the Coast Guard, for example, but this option can be very costly. Calling in rescue professionals can also take some time to implement, depending on how far the nearest Coast Guard facility is from the rescue site, and what mode of transportation (sea and/or air) that the Coast Guard uses to convey itself to the rescue site. A person in the water may not be able to survive even a very prompt Coast Guard response, depending on how far away the rescue location is from the Coast Guard station.
What is needed in the art is a crew overboard retrieval system which can be used to safely and quickly retrieve an overboard crew in difficult conditions, even when shorthanded, and with a minimum of retrieving crew training and expertise, and which is affordable.